Human Nature
by RougeaufSherlock
Summary: Johnlock smut.
1. Chapter 1

"John, you and I are both scientists, wouldn't you say?"

Sherlock took a few slow, long strides toward John, who was standing at the kitchen table.

"You are more of a Biologist, aren't you, Doctor? You understand the human body... all its _needs_.."

His words had turned into a purr. He gripped John by the arm and spun him around to face him, then cupped his cheek. Instead of fear or nervousness, John's eyes widened in awe, and he instinctively slicked his tongue over his soft, pink lips. Sherlock smiled. He was hungry. He wanted every bit of the man before him.

"Why is it that I need you so much?" He reached for the first button on John's red shirt, and popped it with ease.

"Sherlock what-"

"Shh. Call me Mr. Holmes," he said, concentrating on the second button button. After the third, Sherlock lost his patience and ripped the remainder of John's shirt open, causing a few buttons to clatter on the floor and table.

It felt as if all of the blood circling the outside of his brain drained into his prick, and it happened all so fast he became light-headed. Sherlock saw the rapid stimulation in John's eyes, in his breathing, and he pressed his waist into John so that they could feel their erections grow together.

"Tell me, doctor," Sherlock slid his arm over the curve of John's lower back and lightly brushed his fingers through John's hair. "What is it about this kind of intimacy that makes the body react in this way?"

John could hardly think. His train of thought had move to...other areas. "Because," he breathed, searching for words.

Sherlock pressed his lips to John's mouth, sucking in his scent and his clean flavor, but he pulled away before John wanted him too. John begged for more, but Sherlock would not allow it.

"Hormones scatter throughout the body..." John pulled Sherlock closer then, interrupting what he knew was a pointless lesson. He was hungry for Sherlock's lips, hungry for his smoky taste, hungry for the feel of his tongue, hungry for the pulse of his cock, but Sherlock refused to satisfy him so soon.

"Stimulates rapid heart rate, blood flow...-" Sherlock dipped down again and took John's mouth, parting his lips with his tongue. John invited him in, allowed their tongues to explore and play. Sherlock grinded his erection into John's, and John felt his pants were too constricting. Sherlock brushed his teeth over John's lower lip, and John tried to pull him back in, knowing very well Sherlock was going to pull away again, but he missed. Sherlock was teasing. Sherlock liked to tease and John hated it.

"I think you need a lesson, Doctor. I think you're starting to forget."

John fumbled for words, trying to get back on top of the dynamic, but Sherlock was forcing him so deliciously into submission. "Yes Sherl-"

Sherlock shook his head.

"-Yes Mr. Holmes."

Sherlock undid John's trousers and then his own, and their clothing fell to the floor in near unison. Sherlock looked at John's erection. He stared at it. He let him know how much he wanted it.

"Let's try something _hands on_. You'll never forget again."

John felt like he was trying to swallow a rock. Sherlock circled John, and he looked ravenous.

"Let me take you on the sofa. Let me take you over the desk."

He pierced John with his eyes and shepherded him to the den. "Let me take you on the floor, against the wall."

John's heart was pumping rapidly, and he could feel each thud simultaneously in his chest _and _cock. He wanted Sherlock just as much as Sherlock made it clear he wanted John. Sherlock was so enigmatic, so _forbidden_ and that made it all the more exciting.

Sherlock backed John up the empty wall.

"You're mine," he said.

"Take me Mr. Holmes."

"That's what I like to hear."

He slammed John up against the wall and rubbed his erection over his back, running his lips over the side of John's neck and smoothly swaying his hips back and forth.

John was leaking with pre-cum and his face was contorted with desperation. Sherlock rubbed his hands over John's stomach, down his v-line, and then gripped his thighs and pulled his legs apart. John whimpered.

Sherlock purred into his ear. "Let me desecrate you. I'll change who you think you are. You and all your entirety are mine."

"Yes Mr. Holmes," he breathed.

With another strong tug, he pulled John's legs wider apart successfully making him bend over, exposing the elastic entrance.

"Don't forget to breathe" he whispered.


	2. Chapter 2

Sherlock wet two fingers with the lubricant he kept nearby, planning for this very moment, and pushed them into John's pink hole weaving them around and stretching the tender skin.

"Do you like that?" Sherlock asked.

John couldn't muster the words, so he nodded quickly, squeezing his knuckles as Sherlock dug more deeply with his cool, wet fingers. John started panting, but Sherlock was unwilling to have mercy so quickly.

He removed his fingers hastily, causing John's knees to buckle, and reached around to grab John's erection.

"I love your throbbing cock."

His voice vibrated throughout John's entire body, making him shiver. He began stroking, and John throbbed harder with each and every pull.

"Oh God just finish me off already!" he panted.

"Oh the floor." Commanded Sherlock, completely denying his plea.

"Yes Sherlock."

"No," Sherlock purred.

"Mr. Holmes," John corrected.

They lowered together, John still up against the wall, though now on his knees. Sherlock flipped him around so that John faced him now, shoulders against the wall.

"I want to see your face when you orgasm," said Sherlock. John gulped. Sherlock parted his legs and inserted himself into John's loosened entrance. He thrust slowly at first. John was now barely propped up on the wall, grasping desperately for some sort of support on the empty floor, and finding nothing. He reached for Sherlock's back instead, squeezing his fingers around his hips. Sherlock thrust harder, his prick pushing far in and then barely pulling back out. The bookshelf beside them shook, threatened to fall over.

John could feel the pulsing of Sherlock's erection inside him, each beat taking turns with his own.

"Scream, Doctor. I want you to scream. Scream like the animal you are."

"But Mrs. Hudson-"

"-Scream!" he commanded.

Sherlock pushed him harder against the wall, and John let out a scream loud enough to rouse the entire street. They heard a plate shatter downstairs.

John couldn't take it anymore. The drumming of his cock grew harder, faster, he wanted to burst. He was as hard as he thought he could be. Sherlock took him at hand and with three good pulls, John spurted out all over Sherlock's chest and face.

Sherlock received it well. He looked carnal, licking away John's salty white after-math.

He thrust harder yet, faster, squeezing John's hips enough to bruise him. His breathing intensified, and his eyes were entirely focused on the look of sweet relief over John's face, but Sherlock himself looked quite the opposite. He looked desperate, pain-stricken. John was mesmerized by his concentration, the pure look of pleasure as Sherlock reached his peak. The dual enjoyment of his orgasm. Sherlock groaned breathily and erupted into John, relieving all of his tension, pulling out to leave a sticky white trail on the floor. John lifted his legs at the feeling, accepting him gratefully.

Sherlock pulled John away from the wall and lay over top of him, pressing scrotum into John's, letting the puffy organs roll on and compress each other. Then he rolled to John's side, brushed his hand over his hair, and lightly pressed a kiss to his forehead.

It's a wonderful thing, isn't it?" He graced another kiss to John's lips. "Human nature."


End file.
